1. Technical Field
The present invention relates to a high-power semiconductor laser device as a light source for welding, joining, and cutting in the industrial field. It also relates to a method for manufacturing the same.
2. Background Art
In recent years, a significant progress has been made in increasing output performance of semiconductor laser devices. Manufacturers in the industrial field have big expectations for semiconductor laser devices as the light source used for various processes, for example, welding, joining, and cutting.
Having a compact structure, a semiconductor laser device efficiently produces a lot of elements at the same time by a semiconductor wafer. With the advantages above, the semiconductor laser device is suitable for a small light source for tens-of-watts of output. For such a light source for high-power laser with tens-of-watts of output, an arrayed semiconductor laser device or a combined structure of a plurality of stand-alone semiconductor laser devices are employed. An arrayed semiconductor laser device has a plurality of adjacent active regions in a single chip. On the edge of a chip, the device has a plurality of adjacent emitting points, i.e., emitters. A stand-alone semiconductor laser device has a single emitter.
The laser light fed from a semiconductor laser device can be concentrated into several micron scale. With the high capability of light-gathering, a semiconductor laser device focuses light energy on an extremely small area, providing an optimal pinpoint process.
The semiconductor laser devices above work with a light output ranging from approximately ten watts to tens of watts. Compared to laser devices with hundreds of milliwatts scale of output used for optical disks, the aforementioned semiconductor laser devices have extremely large actuating current and a large amount of heat generation in the active regions. Therefore, to obtain high reliability of the devices, i.e., to maintain high output and long-life operation, what important is quick heat dissipation from the active, regions to the outside so as to suppress the temperature rise in the active regions.
To address the problems above, semiconductor laser devices capable of enhancing heat dissipation of a chip have been suggested (see Japanese Unexamined Patent Application Publication No. H01-281786, No. 2008-311491, No. 2010-40933, for example). A conventional semiconductor laser device shown in patent literature 3 will be described with reference to FIG. 15.
FIG. 15 is a perspective view of conventional semiconductor laser device 100. According to conventional semiconductor laser device 100, as shown in FIG. 15, semiconductor laser element 101 is mounted on heatsink 103 via solder layer 102. Conventional semiconductor laser device 100 emits laser light 104 from the laser emission surface (i.e., from the front surface seen in FIG. 15) of semiconductor laser element 101. In conventional semiconductor laser device 100, semiconductor laser element 101 is connected to heatsink 103 with solder layer 102 so that the laser emission surface of element 101 is level with the side surface of heatsink 103.
The structure above protects laser light 104 from being blocked by heatsink 103; at the same time, heatsink 103 sufficiently dissipates heat of semiconductor laser element 101.